Fans, whether applied in an industrial, residential, or other setting, generate noise during operation. Not only can a motor powering a fan generate noise, but the interaction of the air moved by the fan with the fan blades (e.g., the impact between the air and the fan blades), can also generate noise. At times, fan noise is not problematic—for example, even significant amounts of noise in an industrial setting may be of no concern. But at other times, and perhaps in other applications, fan noise is problematic, and a reduction, or attenuation thereof, may afford benefits to those in the area of the fan. More particularly, those within “aural” range of the fan may find a reduction in fan noise reduces disturbance caused by the fan. Even where a fan generated noise is at a low enough level such that one may become accustomed to, and not disturbed by the fan during its operation, the abrupt change from no fan noise to fan noise that takes place during activation of the fan (i.e., “turning on”) of the fan may make a noise level that is otherwise sufficiently low, problematic.
Benefits other than human disturbance mitigation may also flow from reduction, or even elimination of fan noise—improvement in security (certain applications may benefit if individuals are not given aural clues as to the location of a fan (and perhaps equipment it may cool) and/or when it turns on and off); and mitigation of disturbance to wildlife and/or animals. These are just a few of possibly many benefits of reducing (which includes eliminating) fan noise achieved by embodiments of the inventive technology. Note that the inventive technology disclosed herein does not focus on reduction of fan motor generated noise, but instead on reduction of that component of fan noise that is attributable to the movement of air by the fan blades (e.g., by the impact of the air with the fan blades).
While there have been attempts to mitigate fan noise—see, e.g., U.S. Pat. No. 5,088,886—any success has not been without an unacceptably high reduction in some measure of fan performance and/or fan efficiency. Particular embodiments of the inventive technology offer advantages over conventional approaches in that the reduction in noise achieved by embodiments of the inventive technology comes with either no impact on relevant fan performance/efficiency metric(s), or an acceptably small impact on such metric(s).
It is a goal of certain embodiments of the inventive technology to offer a shroud for the inlet area of a fan and to act on inlet air that is moved by the fan, in order to reduce noise of that fan during operation thereof.
It is one goal of certain embodiments of the inventive technology to offer a shroud that may be retrofitted onto an existing fan in order to act on fan inlet air, upon attaching that shroud to the fan (which includes but is not limited to apertured plating, casing, inlet cone, fan housing of any sort, supports for the fan, etc.). Note that certain embodiments of the inventive technology may find application attached to any sort of inlet cone (including but not limited to, e.g., 27004 inlet cone, and the 686qi011, an ideal hyperbolic curve inlet cone).
It is one goal of certain embodiments of the inventive technology to offer a shroud and a fan (whether attached to the fan or as part of a kit that includes the fan and the shroud) available for purchase; the shroud would be suited for use on that fan (e.g., perhaps because it is attachable in some manner to that fan). It is of note that the term fan as used herein may include, but is not limited to, the fan blades, and any motor, casing or housing therefor, in addition to inlet cones.
It is one goal of certain embodiments of the inventive technology to offer apparatus (and associated methods) that reduce fan noise while not unacceptably impairing relevant fan performance and/or efficiency metric(s).
It is one goal of certain embodiments of the inventive technology to offer apparatus (and associated methods) to realign fan inlet flow so that overall it has a greater component that is parallel with (which includes co-linear with) the fan rotation axis, as compared to the case where the inventive apparatus is absent (i.e., not attached to the fan or configured to act on the fan's inlet air).
It is one goal of certain embodiments of the inventive technology to offer apparatus (and associated methods) to redistribute fan inlet flow by increasing the portion thereof that enters a lower resistance sector that his substantially centered around and substantially at a “pole” of the inlet flow area. In such manner, the overall fan inlet flow may have a greater component thereof that is parallel with the fan rotation axis.
It is a goal of certain embodiments of the inventive technology, upon application in a noise limited environment, to allow for greater air moving operation (e.g., fan operation at higher speeds), perhaps to achieve a cooling or other operational goal, while still staying at or below the fan noise limit.
It is one goal of certain embodiments of the inventive technology to offer apparatus (and associated methods) that reduce fan-noise induced disturbance (and associated impacts of fan noise) to individuals in a fan area, without impairing any relevant fan performance and/or efficiency parameter to an unacceptable degree.
It is one goal of certain embodiments of the inventive technology to offer apparatus (and associated methods) to achieve noise reduction and fan performance/efficiency-related goals while minimizing materials and manufacture cost of the inventive apparatus.
It is one goal of certain embodiments of the inventive technology to offer apparatus (and associated methods) that are customized for a given fan application(s).
Of course, other goals, benefits, and advantages of the inventive technology may be disclosed elsewhere in this specification, including the drawings, claims, and written description.
Note that it is not the case that all instances of a given component are called out with reference numbers in the figures. Also, note that the drawings merely show possible examples of particular embodiments of the inventive technology and do not limit its scope.